IN-DEPTH UPDATE

As the landscape industry grows, research supports or disproves common practices. The new American Standard for Nursery Stock (ANSI Z60.1-2004), published by the American Nursery & Landscape Association (ANLA), incorporates recent research and experience. Specifically, it cites a major change in how to measure the depth of the rootball. Over the years, new trees have failed — some quickly, some slowly — due to inadequate root volume in the rootball. Cultural practices in the growing field that call for you to throw soil on top of the ground or for initial planting that is too deep have resulted in newly dug trees with anywhere from 1 to 6 or even 8 inches of soil above the root flare. When the trees are dug under these circumstances, the resulting root volume is deficient due to the large portion of soil above the rootzone. The new standard states that the depth of the rootball shall be measured from the root flare to the bottom of the ball, not from the top of the ball to the bottom. To inspect, simply look for the top of the root flare. You may have to carefully dig down to find it. From the flare, measure down to the base of the rootball to find the true depth of the root system. Trees should be inspected at the nursery or as soon as they are delivered, and you should return those with substandard root depth to the nursery for a replacement.

Additionally, in an effort to assist everyone involved in the landscape industry, from the large companies to the small, the new standard is available FREE online. The Web site is https://secure.rd.net/anla/publications/. Be sure to check it out and thank the ANLA for this service to the industry.